The rails on a railroad are 30 feet long. As the train passes over the point where the rails are joined, there is an audible click. The speed of the train in miles per hour is approximately the number of clicks heard in:
A. 20 seconds
B. 2 minutes
C. 1.5 minutes
D. 5 minutes
E. None of these

How to get a relation between the number of clicks and speed of the train and the time taken by it.

I assumed that the number of clicks has to be an integral value like 1,2,3..... Further i tried to figure out at what distance and at what time the train gives an integral value of the number of clicks. I tried to play with the options.But all in vain.

  1. 👍 0
  2. 👎 0
  3. 👁 68
asked by Gaurav
  1. Please help....

    1. 👍 0
    2. 👎 0
    posted by Gaurav
  2. See how many clicks in 1 minute at 60 mph

    60*5280/30*60=176 clicks in 1 minute

    But they want to know how many seconds for 60 clicks to occur:

    60/176=About 1/3 of a minute, 20 seconds

    1. 👍 0
    2. 👎 0
    posted by KentG
  3. 30 ft (1 m/5280 ft) = .00568 mile

    v = .00568 /T in hours

    T in hours = .00568 /v

    T in seconds = 3600*.00568/v
    = 20.45/v

    clicks/second = 1/T = v/20.45
    v = 20.45 * clicks/second

    1 click/second --> 20.45 mph
    2 clicks/second -->41 mph

    v = 20.45 * clicks/second
    = clicks/20.45 seconds

    so A.

    1. 👍 0
    2. 👎 0
    posted by Damon

Respond to this Question

First Name

Your Response

Similar Questions

  1. history

    Why did the building of the Transcontinental Railroad have to be shelved for a few years? Iron rails rusted, and the wait for steel rails was extremely long. There were not enough workers to complete the building process. Native

    asked by Michael on December 17, 2018
  2. physical

    Steel rails for a train track are laid in a region subject to extremes of temperature. The distance from one juncture to the next is 4.41 m, and the cross-sectional area of the rails is 60 cm2. If the rails touch each other

    asked by itufizik on July 23, 2012
  3. Math - What is the length of the train??????

    I have NO IDEA on how to tackle the following problem. This question has stumped me for like...2 hours now...and I don't know what to do... If someone could please show me a step by step on solving it, please post! Problem:

    asked by Anonymous on November 27, 2007
  4. Physics

    When railroad tracks are installed, gaps are left between the rails. Each steel rail is 8.0m long and has a cross-sectional area of 0.0020m^2. On a hot day, each rail thermally expands as much as 4.0mm. If there were no gaps

    asked by Wendi on December 8, 2010
  5. Mechanics of Materials

    A railroad is laid so that there is no stress in the rails at 20 degrees celcius. Calculate the stress in the rails at -6 degrees celcuis if all the contraction is prevented. Take E=206GPa and linear coefficient of expansion is 12

    asked by Claire on March 6, 2010
  6. algebra

    tains A and train B are travling in the same dicrtion on a parral track train A is traving 60 mph and train B is traviling 70 mph train A passes a staion at 11.15 am and train B passes the same station at 11.45 am at what time

    asked by me on January 24, 2010
  7. school of engineering

    A train of mass 200 tonne travelling at 140 km/hour applies the brakes fiercely, so that the brakes lock and the wheels slide along the rails. It stops after sliding 1000m. Calculate: (i) The acceleration, (ii) The longitudinal

    asked by abdul on October 16, 2013
  8. physics

    A square bar with a mass of 0.830 kg and 19.3cm long (l) rests on two parallel horizontal rails that are 18.0cm apart (d) and 120.0cm long (L) as shown in the figure. (By horizontal it is meant that the rails lie in a plane

    asked by Trisha on February 20, 2015
  9. math

    how many cars are there in a long freight train, if it takes the entire train 4.50 minutes to pass a station at 25.0 miles per hour? Each car is 45.0 feet long. There are 5280.0 feet in a mile.

    asked by niecy on January 15, 2015
  10. 7th grade math Ms. Sue please help I have no idea!

    #10 On a blueprint, 1 inch = 13 feet. If the dimensions of the playroom on the blueprint are 0.35 inches x 1.25 inches, what are its actual measurements? * *Show all your work for full credit* #11 The coordinate of rectangle ABCD

    asked by Delilah on November 5, 2012

More Similar Questions